Log loader apparatus



Jan. 22, 1957 1.. o. M LEAN LOG LOADER APPARATUS 4 Sheets-Sheet 1 Filed April 15, 1952 l'. ll!

INVEN TOR.

his 7 aor-ney Jan. 2-2, 1957 o. MQLEAN LOG LOADER APPARATUS 4 Sheets-Sheet 2 Filed April 15, 1952 INVENTOR.

LELAND o. MCLEAN h is attorne y 1957 L. o. M LEAN LOG LOADER APPARATUS Filed April 15. 1952 4 Sheets-Sheet 3 INVENTOR.

/)/5 azzforney .i'i] LELAND 0. MLEAN 4 Sheets-Sheet 4 Filed April 15, 1952 IN V EN TOR.

v LELAND o. MLEAN has affomey United States Patent LOG LOADER APPARATUS Leland O. McLean, Marion, Ohio Application April 15, 1952, Serial No. 282,399

7 Claims. (Cl. 214-147) This invention relates generally to improvements in log loaders and other material handlers of the crane and tong type, and more particularly to the mechanism for providing a new and improved'arm type boom assembly comprising a boom, a forearm which is pivotally mounted on the boom and from which the tong-assembly is pivotally supported, said forearm being operated by means of a hoist line and a haulback line wound upon two winches mounted on the machinery deck, and a fluid pressure actuated cylinder for opening and releasing the tongs, all being powered and controlled independently from a common source of power, such as an internal combustion engine and a compressor or pump mounted on the machinery deck of the log loader.

One of the objects which I have in view is the provision of improved means for positively positioning the log being handled, also for moving through a greater range, due to the rigid forearm pivotally operable on the end of the boom, instead of merely hoisting the log by means of a rope suspended over the end of the boom or by means of tongs rigidly attached to the end of a shovel dipper handle, thus enabling the log to be handled more easily and with less tearing and scuffing of the log than is the case with the present log loaders now in use.

Another object is to provide improved means for opening the tongs with the tines retracted to properly engage the log with tong-arms extended, which means is controlled by the operator on the machine, instead of requiring a man on the ground to open and place the tongs by hand above the log as is the case with the present crane loaders now in use.

Another object is to provide means for retaining the proper engagement of the tongs about the log due to the freedom of the tongs to pivot and swivel in a limited arc as the relative position of the log to the boom is changed during the handling of the log, instead of tearing and scufiing the log as is the case with the present arrangement with the tongs rigidly attached to the end of the dipper handle, without the-flexibility required to accommodate the varying positions of the log in handling.

Still another object of the invention is the provision of means to engage the tongs about the log when the log is lying in any position,relative to the boom or machine, instead of near the vertical plane of the boom as is the case with the present shovel typelog loader wherein the tongs are rigidly attached to the shovel dipper handle.

Another object is the provision of simple and effective means, easily and safely controlled by the operator of the machine, from the cab, for providing automatic increased gripping of the log in proportion to its weight by tongs that are free to'follow the varying positions of the log throughout its handling, without requiring the assistance of a groundman to engage the tongs nor of a man to assist in disengaging the tongs, thus eliminating the danger of injury or death to the assisting workmen, a common accident in the present practice. v

Another object of my-present invention is the embodying of the principles thereof in a simpler, lighter and less expensive combination which may be mounted on a chassis, such as that of a used truck, which embodiment is especially fitted to handling the logs of less diameter and smaller weight characteristic of the forests in the Southern American States.

Other novel features of construction and arrangement of parts will appear from the following description.

In the accompanying drawings, which illustrate a practical embodiment of the principles of my invention:

Fig. l is a side elevation illustrating the structure of my arm-type log loader;

Fig. 2 is a sectional view on enlarged scale taken on a vertical plane of the tong assembly shown in its closed position;

Fig. 3 is an elevation of the tongs shown in their open position and turned ninety degrees from their position shown in Fig. 2;

Fig. 4 is a view looking from the right in Fig. 1 on the line 4-4 showing the mast of the gantry;

Fig. 5 is a view looking from the right in Fig. 1 on the line 5-5, showing the relative positions of the two winches for the haulback line and the hoist line;

Fig. 6 is a top plan view taken on the line 66 of Fig. 1 showing in detail the twin sheaves mounted on the boom and over which the haulback line runs;

Fig. 7 is a top plan view taken on the line 7-7 of Fig. 1 showing the sheaves pivotally attached to the upper end of the forearm over which the hoist line runs;

Fig. 8 is a top plan view taken on the line 8-8 of Fig. 1 showing the sheaves supported by the forearm and engaged by the haulback line;

Fig. 9 is a top plan view of the tong assembly;

Fig. 10 is a side elevation of a modified form of my improved log loader;

Fig. 11 is a plan view of the deck, the boom, forearm and tong assembly being omitted for the sake of clarity;

Fig. 12 is an end elevation looking from the left in Fig. 11 and showing the gantry and its mounting on the deck; and

Fig. 13 is a sectional view showing the pivotal mounting upon which the boom swings.

Referring first to Figs. 1 to 9, inclusive, of said drawings, 20 indicates the machinery deck of the log loader, which deck, as in common practice, is mounted on the turntable 18 rotatably carried by the undercarriage of a mobile carrier or truck, not shown, the turntable is arranged to rotate relative thereto on a vertical axis 19 which is old in the art, the deck being provided with a motor arranged to selectively drive the undercarriage, swing the deck and operate the boom, forearm, and tongs, as will later be more fully described.

The gantry includes a mast indicated at 21, while the boom is shown at 22. The mast 21 is supported on the pivot pins 21a on the deck at its base and the boom is mounted on the deck to swing on a horizontal axis. The forearm indicated at 23 is pivotally connected at a point intermediate of its ends to the outer end of the boom 22 as by the pivot 23a. The tong assembly indicated at 24 is pivotally suspended from the lower end of the forearm.

The gantry is provided with twin diverging stay straps 25 which connect the upper-end of the mast 21 to the machinery side frames 25a, one of which frames extends upwardly from the deck at each side of the latter adjacent its rear.

The mast 21 is divided vertically into two side portions, one of which is provided with a lattice cross bracing 26 to add strength, while the other side of the mast is open, as shown at 27, for the passage of the haulback line 28 tothe winch 39, the right hand winch as shown in Fig. 5,

The haulback line indicated at 28 leads forward over the sheave 29, one of a pair of sheaves 29 and 2% shown in Fig. 6, which are journaled on the opposite ends of an axle 39 that extends transversely of the boom 22, intermediate the ends of the latter, and is supported above the boom in the bracket 31 extending upwardly from the boom. From the sheave 2 the haulback line extends forwardly under a fairlead roller 32, see Fig. 8, and then is turned around the twin sheaves 34 and 3&0 which are journaled in spaced relation on vertical axes adjacent to the opposite ends of a sheave block 35, which block is pivotally supported on a pin 36 carried by a bracket 37 fixed on the forearm 23 adjacent to the end of the latter, to which the tong assembly is attached. The hardback line thence extends rearwardly under the fairlead roller 32a, mounted adjacent the other end of the sheave block 35, and over the sheave 22% mounted on the boom, and thence to the dead-end socket 38 which also is mounted on the boom.

A pair of winches 39 and 4d are mounted, preferably, side-by-side between the machinery side frames of the deck, as illustrated in Fig. 5. Each of said winches is provided with independent means for the power-rotation of the winch and for locking it stationary.

The winch. 44 the left-hand winch in Fig. 5, has spooled to receive the end portion of the hoist line 41, while the winch 39, the right-hand Winch in Fig. 5, has wound about it the end portion of the haulback line 28, as shown in Fig. 5.

The hoist line d1 extends forwardly and upwardly and over the sheave 4-2, one of a pair of sheaves 4 2;v and 42a rotatably mounted on a common axle carried by the upper end of the mast 21, as shown in Pig. 4. Thence the hoist line ll extends forwardly and around a sheave 43 of a pair of sheaves 43 and 43a (Figs. 1 and 7), which are rotatably mounted on a common axle 44 in a sheave block 45, which block is supported by the free ends of a pair of parallel arms 45a, which extend forwardly and between the forked upper end portion of the forearm and are pivotally attached thereto by a pivot 46 carried by the upper end of the forearm 23.

From the sheaves 43 the hoist line extends rearwardly and in turn around the sheave 42a on the gantry, and thence forwardly and around the sheave 43a on the sheave block 45, and thence rearwardly to a dead-end 4-9 on the upper end of the mast 21.

A single-acting fluid pressure cylinder St) is secured on the forearm 23 as by the bolts Slia intermediate of the ends of the forearm. The piston within the cylinder 56 is shown at 51. 53 is the piston rod which extends out through the front end of the cylinder.

The front end of the cylinder 50 is connected to a supply or source of compressed air or hydraulic pressure 55 which is mounted on the deck 29 by the pipe 56 which is connected to the front end of the cylinder and extends back along the forearm and boom to the deck 20 where it is provided with a control valve 57 arranged to admit pressure to the cylinder 54 when the valve is open or to exhaust pressure from said cylinder when the valve is closed. The pipe 56 is provided with flexible intermediate portions 56a which connect the pipe about the pivotal connections between the forearm and the boom and between the boom and deck.

The adjacent extremity of the forearm, the lower end as shown in Fig. 1, is forked to. provide a pair of parallel spaced apart extensions 58 and 58a (see Fig. 3) which are provided with aligned pivot pin holes. The tong head 59 is provided at its top with two pairs of parallel and spaced vertical wings 60 and Gila. When the tong head is to be pivotally attached to the forearm, in completing the tong assembly, the spaced extensions 53 and 58a of the forearm are nested between the members of two pairs of vertical wings 69 and 60a, which wings are provided with pivot pin holes aligned with the holes in the forearm extensions. The pairs of wings are positioned on the top 4 surface of the tong head 59 at equal distance from and diametrically aligned with the opposite sides of the bore of the center post. The tong head 59 is annular, having an axial opening 59a in which is rotatably engaged the enlarged head of the center post to be described. The pivot pins 61 and 61a extend through the aligned holes in the Wings 60 and Mia. The pin 61a is held stationary by the bolt 61b. The pivot pins 61 and 61a at their inner ends are spaced apart to provide clearance for the two parallel frames 63 bolted onto the tong head and are spaced apart sufiiciently to provide room for a pair of sheaves 64 which are rotatably mounted on pivot pins 65, which pins are journaled in holes in the spaced frames 63 and are held in place by set screws The two sheaves 634- are aligned and in proper proximity to receive between them and guide the tong-opening rope 66, the upper end of which rope is attached to the protruding piston rod 53 of the cylinder 50.

The rope 66 extends from above down over a guide sheave 67 mounted on the forearm and directed down between the twin sheaves 64.

A split ring retaining means 68 is removably attached as by bolts 69 tothe underside of the tong head 5% to hold in place the antifriction bearing 70, through which hearing extends the reduced lower portion of the center post 71. The enlarged circular top 72 of the center post rotates in the axial bore of the tong head, being supported in position by the bearing 70.

The perimetral edge of the holding ring 68 is provided with two depending lugs 73 spaced 180 apart, and extending outwardly between said lugs 73 are two similarly placed lugs 73a carried on an annular collar 74. Thus the possible rotary movement of the collar relative to the tong head is limited to 180.

The lower stem portion of the center post 71 extends down through the bore of the collar 74 and is fixed to rotate in unison with said collar by means of a key 75 engaging mating grooves in the post and collar. Vertical movement between the collar and center post is prevented by the split ring 76 engaging corresponding grooves in the post and collar.

The tong-opening rope 66. is directed by the sheave 67 down between the twin sheaves 64 and through the axial bore of the center post.

Pivotally attached to the collar 74 at diametrically op posite points are the suspension straps 78, the lower ends of which are pivotally connected to the upper ends of the curved tong arms 79 which cross each other and are pivotally connected by the pivot member 8% to which the lower end of the. rope 66 is attached. Below the pivot, 80 the tong arms separate.

Thus it is apparent that an upward pull on the rope 66, as by the admission of; fluid pressure into the front end of the cylinder 50, would cause the lower end of the tong arms to be moved apart and thus release the log. I provide a spiral spring 81, through which the rope 66 extends, the lower end of which spring bears against the pivot member 80 which pivotally connects the tong arms, while the upper end of the spring bears against the annular shoulder 81a formed by the upper end of the lower portion of the bore of the centerpost, which spring causes the initial engagement of the log and exhausts the air or fluid from the cylinder 50 when pressure is released. Further engagement is self-energized by the weight of the log as lifted. When pressure is admitted to the cylinder 50, the pull on rope 66 is much greater than required to compress the spring 81, thus releasing the log when the latter has been properly positioned for loading.

To aid in properly adjusting the tong arms in proper straddling position as they are lowered from above the log, I provide novel means. for controlling the rotation of the tongs. Thus I provide a gear 82 which is fixed on the flat upper end of the. center post 71 with its. axial opening aligned with the bore of the latter. A second gear 83 is rotatably mounted on the overhanging inner end of the pivot pin 61a, which gear 83 has its teeth engaged with those of the gear 82. The gear 83 has integral with its hub a rope drum 84, which drum has an outer flange 85 to prevent the rope, later described, from slipping off the drum.

A rope or handline 86 is doubled and has its end portions wound in opposite directions on the drum 84 and said ends are dead-ended to the drum. The double portion of the line extends from the drum 84 to the gantry over a series of double pairs of pulleys, the line first passing up over the pulleys 88 mounted on the forearm and thence over the pulleys 89 at the end of the boom, and thence through the interior of the boom to pulleys 90 at the inner end of the boom aligned with the pivotal support of the boom, and thence upwardly and around pulleys 91 mounted in the structure of the deck cabin, and thence down and with its center loop extending around the pulley 92 which is spring-connected to the deck at 93. A hand grasp 94 is secured on each of the strands of the line between the pulleys 91 and pulley 92, so that the engineer may grip either of the grasps 94 on the two strands of the line and thus rotate the gear 83 and with it the gear 82,

thus rotating the center post and enabling the engineer to accurately spot the tong arms in proper straddling position relative to the log.

Referring next to Figs. to 14, inclusive, of the drawings, 1 illustrate therein a log loader which embodies the principles of my present invention in a less expensive structure than that illustrated in the preceding views, and which embodiment may be inexpensively mounted on the chassis of a used or new bus or truck. This structure is especially useful in loading logs of lighter weight than those which would require the heavier structure shown in Figs. 1 to 9, inclusive.

In this second structure I illustrate the use of hydraulic power to raise and lower the boom, swing the boom throughout 180, operate the forearm, and open the tong arms. Thus in the side elevation shown in Fig. 10, 120 indicates the stationary deck of the log loader which is mounted in turn on the motor driven chassis, not shown. Near its front end the deck has erected thereon a vertically disposed bearing member 121. Rotatably mounted and journaled in the bearing is the depending journal 122 depending axially from the enlarged gear wheel 123 which is elevated above the deck 120. The toothed perimetral edge of the gear 123 is engaged by the sprocket chain 124, the extremities of which are connected to the protruding piston rods 125 and 126 of the pair of parallel single-acting hydraulic cylinders 127 and 128. Thus by means of the proper one of the nest of control levers 129 mounted on the mast above the deck, the gear 123 may be rotated in either a clockwise or counterclockwise direction, as pressure is admitted toone cylinder and exhausted from the other.

The boom 130 is pivotally mounted at its base on the top surface of the gear 123 as at 131 on a horizontal axis. Thus the boom rotates with the gear on a vertical axis.

The mast 132 which is preferably of open frame construction, has its horizontal base member 133 secured at its lower end to the deck, at the rear of the gear 123. The gantry is stayed by a pair of straps 134 which extend rearwardly and downwardly and are secured to the' rear end of the deck.

A double-acting hydraulic cylinder 135 has its rear end pivotally connected by a universal pivot connection 136 to the upper end of the mast 132 and at the front end of said cylinder the protruding piston rod 137 is pivotally connected at 137a on a horizontal axis to the boom 130 intermediate of the ends of the latter.

Thus by operating the proper lever 129 of the bank of such levers mounted on the gantry pressure is admitted to the outer end of the cylinders 135 to elevate the boom as the pressure is exhausted from the other end of the cylinder, and when pressure is admitted to the rear end of the cylinder the pressure is exhausted from the outer end of the cylinder to lower theboom.

A second double-acting hydraulic cylinder 138 has its rear end pivotally attached at 139 on a horizontal axis to the boom 130 at a point between the pivotal attachment of the piston rod 137 and the outer extremity of the boom. The piston rod 140 of the cylinder 138 is pivotally connected on a horizontal axis with the upper end of the forearm 141 which is pivotally connected on a horizontal axis at 142 to the outer end of the boom 130. Mounted axially on the forearm is the third double-acting hydraulic cylinder 143 and the protruding outer end ofits piston rod 144 is attached to the end of the tong-opening rope 145. The tong assembly 146 is pivotally attached to the other end of the forearm and the tong-opening rope is attached to the pivotal connection between the two tong arms in the manner illustrated and disclosed in connection with the views 1 to 8 inclusive of the drawings.

The fluid pressure supply is provided by the pumps 147 driven by the engine of the truck. 148 is the tank to which the fluid exhausted from the cylinders is returned and from which the pumps 147 receive fluid. The pressure is admitted to or exhausted from the cylinders by means of proper control levers of the bank 129 mounted on the gantry. 149 represents the seat for the operator mounted on the deck and located to the rear of and within reach of the bank of levers 129.

The tong assembly is the same as shown in Figs. 1 to 9, inclusive, and the fluid pressure supply from the pumps 147 is led to and from the various cylinders by suitable pipes with flexible connections by-passing the points of oscillation. I 1 -The mechanism of the tong assembly which is carried by the forearm 141 is the same as illustrated and described in connection with Figs. 1 to 9, inclusive, of the drawings and the control of the rotary center post and the manner of rotating the tong arms and holding the same in their adjusted position is also the same. i

I claim:

1. In apparatus for loading logs and the like, the combination of a support, a gantry extending upwardly from said support, a boom mounted on said support and pivotally connected thereto on a horizontal axis, a fore arm pivotally connected on a horizontal axis to the outer end of said boom, a plurality of sheaves mounted on the upper end of the gantry and on the upper end of the forearm, a pair of winches mounted on the support, a hoist line having one end wound about one of the winches and having its intermediate portion weaved between the sheaves mounted on the gantry and the sheaves mounted on the forearm, the other end of said hoist line being dead-ended on the gantry, a haulbackline having one of its ends Wound about the second winch, a sheave attached to the lower end of the forearm, the intermediate portion of the haulback line extending around said last mentioned sheave and dead-ended on the boom, a fluid pressure cylinder mounted on the forearm and having a piston rod protruding through the front end of the cylinder, a rope attached to the protruding end of the piston rod, and a tong assembly pivotally connected to the lower end of the forearm and actuated by said rope.

2. In a crane, the combination of a support, a gantry mounted on the support, a turntable mounted on said support to pivot on a vertical axis, a boom having its inner end pivotally connected to said turntable to swing in a vertical plane, a forearm pivotally attached on a horizontal axis to the outer end of the boom, pivotally connected together tong arms pivotally attached to the lower end of the forearm, a two-way fluid pressure cylinder having its one end attached to the upper end of the gantry by a universal connection and having the outer end of its piston pivotally connected to the boom intermediate the length of the latter, a second double-acting fluid pressure cylinder pivotally connected at its one end on a horizontal axis and having the outer end of its piston rod pivotally connected to the upper end of the forearm, a pair of one- .having their respective piston rods flexibly connected to the opposite sides of the turntable, whereby the turntable and the boom may be rotated on a vertical axis, and a third single-acting fluid pressure cylinder mounted longitudinally of the forearm and having the outer end of its piston rod connected by a flexible line to the pivotal connection between the tong arms whereby when fluid pressure is admitted to the front end of the said cylinder the tong arms will diverge but when said pulling force ceases said tong arms will converge.

3. The structure of claim 2 characterized by the pro vision of means for rotating the tong arms into proper position relative to the log to be grasped.

4. In a machine for loading logs and the like, the combination of a deck, an arm member carried by the deck and movable on both a vertical and a horizontal axis relative to the latter, an annular head ring pivotally attached to the end of the arm member on a horizontal axis, a stem member having a circular upper end journaled in said head ring and depending therefrom, a tong assembly attached to the lower end of the stem member, means operable from the deck for rotating the stem member to properly position the tong assembly relative to the log, the stem member being provided with an annular set of gear teeth and a gear wheel meshed with the same, and means for rotating said gear Wheel from the deck to rotate said gear wheel and said stem member to properly position the tong assembly.

5. In a machine for loading logs and the like, the com bination of a deck, an arm member carried by the deck and movable on both a vertical and a horizontal axis relative to the latter, an annular head ring pivotally attached to the end of the arm member on a horizontal axis, a stem member having a circular upper end journaled in said head ring and depending therefrom, a tong assembly attached to the lower end of the stem member, means operable from the deck for rotating the stern member to properly position the tong assembly relative to the log, the stem member being provided with an annular set of gear teeth which are meshed with a gear wheel rotatably mounted on the head ring, a drum fixed to said gear wheel, a doubled line having its free ends Wrapped about said drum in opposite directions and having its intermediate loop supported on the deck, whereby the gear Wheel may be rotated in a selected direction by pulling the proper strand of the doubled line.

6. In a machine for loading logs and the like, the combination of a deck, an arm member carried by the deck and movable on both a vertical and a horizontal axis relative to the latter, an annular head ring pivotally attached to the end of the arm member on a horizontal axis, a stem member having a circular upper end journaled in said head ring and depending therefrom, a tong assembly attached to the lower end of the stem member, means operable from the deck for rotating the stem member to properly position the tong assembly relative to the log, the stem member being provided with an annular set of gear teeth which are meshed with a gear wheel rotat ably mounted on the head ring, a drum fixed to said gear wheel, a doubled. line having its free ends wrapped about said drum in opposite directions and having its intermediate loop supported on the deck, whereby the gear wheel may be rotated in a selected direction by pulling the proper strand of the doubled line, the line being connected to the deck by being passed around a pulley which is spring-connected to the deck, thus preventing slack in the line.

7. In apparatus for loading logs and the like, the combination of a support, a boom mounted on said support and pivotally connected thereto on a horizontal axis, a gantry extending upwardly from said support for supporting said boom, a forearm pivotally connected on a horizontal axis to the outer end of said boom, actuating means for said boom and forearm, a fluid pressure cylinder mounted on the forearm and having a piston rod protruding therefrom, a rope attached to the end of the piston rod, a pivoted swivel on the outer end of said forearm, a tong assembly including a pair of tong arms pivotally connected intermediate their ends, a link connecting the upper end of each tong arm to said pivoted swivel on the end of said forearm, the other end of said rope attached to the pivoted connection of said tong arms to open the same when pulled, and means for rotating said tong arms on said swivel to properly position them as the tongs are lowered to straddle a log.

References Cited in the file of this patent UNITED STATES PATENTS 477,621 Bulmer June 21, 1892 513,658 Smith et al. Ian. 30, 1894 542,997 Dinkey July 23, 1895 754,910 Taylor Mar. 15, 1904 1,327,324 Hecker Ian. 6, 1920 1,420,733 Mundy et al June 27, 1922 1,499,938 Leedom July 1, 1924 2,272,949 Kidder Feb. 10, 1942 2,305,566 Weston et al. Dec. 15, 1942 2,486,479 Kennedy Nov. 1, 1949 2,577,689 Morin Dec. 4, 1951 2,651,424 Johnson Sept. 8, 1953 2,656,212 Eckstein Oct. 20, 1953 2,702,137 Ives Feb. 15, 1955 FOREIGN PATENTS 389,858 Great Britain Mar. 27, 1933 

